This 6,000-year-old tomb might be the world's first telescope

The
orientation of the tombs suggests that they are aligned to offer
a view of Aldebaran, the brightest star in the constellation of
Taurus.University of Wales Trinity
Saint David/Nottingham Trent University

Prehistoric tombs may have offered more than just a resting place
for departed souls many millennia ago.

According to researchers in the UK, 6,000-year-old passage graves
in Portugal could also have served as the first lens-less
astronomy telescopes, creating a tunnel vision effect that would
have made it easier to observe the stars above.

"The key thing is that a passage grave with its long corridor
acts like a telescope that does not have a lens – it is a long
tube from which you are looking at the sky," astronomer Fabio
Silva from the University of Wales Trinity Saint David told
Nicola Davis at The Guardian. "Its characteristics
are going to impact how you are looking at the sky in three or
four ways."

This includes directing your attention to a particular portion of
the sky, while also blocking out the distraction of other stars
and planets. In addition, it's possible that the lightless
environment of the megalithic structure would help your eyes
adjust to the dark, making it easier to discern faint details
such as distant stars.

"All you are doing is making sure everything is dark apart from
that small area in the sky," says another of the team, Daniel Brown from
Nottingham Trent University.

The team thinks that a number of these passage graves in
Portugal, including the Seven-Stone Antas in central Portugal, have
entrance ways that aren't positioned by accident.

"The orientations of the tombs may be in alignment with
Aldebaran, the brightest star in the constellation of Taurus,"
Silva said in a press release. "To accurately
time the first appearance of this star in the season, it is vital
to be able to detect stars during twilight."

The researchers suggest that prehistoric peoples might have used
the tombs as calendar aids, helping them mark the shift of
seasons so they knew when to move to higher grounds in the
spring. They could also have served as ritualistic devices,
conferring special knowledge to those allowed inside the graves,
or in rites of passage involving the young.

"Imagine a young boy forced to spend the night in the passage –
probably scared to death," Silva told Clare Wilson at New Scientist. "In the morning he
would see this star rise days before the rest of his tribe. That
may have been presented as secret knowledge."

There
may have been a ritual significance to viewing the night sky from
the tombs.University of Wales Trinity
Saint David/Nottingham Trent University

The team presented their study at the National Astronomy
Meeting in Nottingham this week, and they're now looking to
expand on their hypothesis by replicating the viewing conditions
that the passage grave telescopes could provide.

"We are going to simulate this star rising at twilight conditions
and allow people to tell us when they can see it," Silva told
The Guardian. "Then [we will] compare
that with a control group of people that are in a room which
would replicate the conditions of being outside the passage
grave."

The research could also help shed light on what other forgotten
purposes these ancient tombs once had. A large number of Europe's
passage graves share another unexplained coincidence, aside from
the Aldebaran connection being examined in the new study.

The
passageway’s long corridor acts like a telescope without a
lens.University of Wales Trinity
Saint David/Nottingham Trent University

"There are more than a thousand passage graves along the Atlantic
coastlands of northwest Europe. How they were used has been a
question on the lips of many archaeologists for centuries,"
archaeologist Timothy Darvill from Bournemouth University in the
UK, who was not involved with the study, told Sarah Knapton at
The Telegraph.

"Some, including the well-known examples at Newgrange in Ireland
and Bryn-celli-Ddu on Anglesey, seem to have been orientated
towards either the sunrise or sunset on the summer or winter
solstice," he added. "But only about 10 percent of
passage graves seem to have these orientations. It would be
wonderful if the proposed research could identify patterns that
apply to the other 90 percent."